潜孔锤反循环钻进岩屑粒度分布规律

研究岩屑粒度分布规律有利于进一步分析潜孔锤反循环钻进的碎岩机理。采用分布函数和分形方法对反循环钻进产生的岩屑粒度分布进行描述，并得到岩屑粒度分布规律。结果表明：试验用岩屑的粒度分布符合Gandin-Schuhmann分布和Rosin-Rammler分布，其中岩屑颗粒更贴近于G-S分布；岩屑粒径遵循分形规律，可以用分形方法描述反循环钻进中岩屑粒度的分布特征。从岩屑粒度分布来看，大于5 mm的颗粒占总质量的74.8%，表明潜孔锤球齿破碎岩石以体积破碎为主；块状颗粒分布在5~12 mm，说明岩石的体积破碎存在大小差异，并伴随有重复破碎。

Grain Size Distribution Law of Cuttings in DTH Hammer Reverse Circulation Drilling

Research on grain size distribution law would be helpful to further analysis on rock broken mechanism of DTH hammer reverse circulation drilling.The grain size distribution of cuttings in DTH hammer reverse circulation drilling was described by distribution and fractal function,and its distribution law was obtained.Results showed that the grain size distribution of cuttings conform to Gandin-Schuhmann distribution and Rosin-Rammler distribution,and much closer to G-S distribution.The cutting grain size distribution characteristics of reverse circulation drilling follow the fractal rule and can be described by fractal method.The grain size distribution indicates that the total mass of cuttings greater than 5 mm is 74.8%,which shows a predominant volume broken of rock by DTH hammer.The size of massive particle is between 5 mm to 12 mm,indicating the size difference in volume broken accompanied by repeated crushing.